Search results

Filter

Filetype

Your search for "*" yielded 530187 hits

Ions in models of articular cartilage : The importance of electrostatic interactions for transport and equilibrium distribution

Artros är en vanligt förekommande ledsjukdom som kan leda till stelhet ochsmärta i den drabbade leden. Sjukdomen innebär att det sker en nedbrytning av det brosk som fungerar som smörjmedel och skyddande lager runt benändarna i leden. Nedbrytningen av brosket sker gradvis under flera år och oftast upptäcker man sjukdomen först i ett sent stadium när man börjar känna smärta eller få problem med rörOsteoarthritis (OA) is a degenerative disease that affects articular cartilage, which covers the surfaces of the bones in synovial joints. At later stages the disease can result in major loss of articular cartilage and thus lead to major disability. In order to allow for an early detection and treatment of OA, it is necessary to better understand the rather subtle biochemical changes in the cartil

The Burden of Mental Disorders in the Eastern Mediterranean Region, 1990-2013

The Eastern Mediterranean Region (EMR) is witnessing an increase in chronic disorders, including mental illness. With ongoing unrest, this is expected to rise. This is the first study to quantify the burden of mental disorders in the EMR. We used data from the Global Burden of Disease study (GBD) 2013. DALYs (disability-adjusted life years) allow assessment of both premature mortality (years of li

Thermodynamic analysis of siphon flash evaporation desalination system using ocean thermal energy

Ocean thermal energy refers to the thermal potential energy produced by the temperature difference between the warm surface seawater and the cold deep seawater. In this paper, a siphon flash evaporation desalination system using ocean thermal energy is proposed. Because it can utilize the ocean thermal energy directly for desalination, siphon flash evaporation desalination system has relatively hi

Effects of pitch and corrugation depth on heat transfer characteristics in six-start spirally corrugated tube

Spirally corrugated tube is one of the most important parts of coaxial heat exchangers. It can greatly improve the heat transfer efficiency of heat exchangers. Here, a novel spirally corrugated tube with six-start is proposed. However, up to now, there is little literature about the heat transfer performance and flow field of this novel six-start spirally corrugated tube. In this paper, the effect

Field synergy analysis of six starts spiral corrugated tube under high Reynolds number

Coaxial heat exchanger is widely used in air conditioning, refrigeration etc., due to its highly efficient heat transfer performance. Spiral corrugated tube plays an important role in coaxial heat exchanger. In this paper, the numerical model of a six starts spiral corrugated tube and a smooth tube with the same size are developed. The temperature field and the velocity field of their streamline a

Dynamic response analysis of pilot control globe valve focusing on opening and closing time of pilot valve

Pilot control globe valve (PCGV) can use the pressure difference produced by fluid itself to realize the opening and closing states with a pilot valve. In this paper, numerical method is used to investigate the fluid flow characteristics and the valve core movement inside PCGV under different opening and closing times of pilot valve. The result shows that, shorter opening and closing time of valve

Hedging lookback and partial lookback options using Malliavin calculus

The paper considers a Black and Scholes economy with constant coefficients. A contingent claim is said to be simple if the payoff at maturity is a function of the value of the underlying security at maturity. To replicate a simple contingent claim one uses so called delta-hedging, and the well-known strategy is derived from Itô calculus and the theory of partial differentiable equations. However,

Bonds and Options in Exponentially Affine Bond Models

In this article we apply the Flesaker–Hughston approach to invert the yield curve and to price various options by letting the randomness in the economy be driven by a process closely related to the short rate, called the abstract short rate. This process is a pure deterministic translation of the short rate itself, and we use the deterministic shift to calibrate the models to the initial yield cur

Two Exotic Lookback Options

This paper formally analyses two exotic options with lookback features, referred to as extreme spread lookback options and look‐barrier options, first introduced by Bermin. The holder of such options receives partial protection from large price movements in the underlying, but at roughly the cost of a plain vanilla contract. This is achieved by increasing the leverage through either floating the s

Hints for an extension of the early exercise premium formula for American options

There exists a non-closed formula for the American put option price and non-trivial computations are required to solve it. Strong efforts have been made to propose efficient numerical techniques but few have strong mathematical reasoning to ascertain why they work well. We present an extension of the American put price aiming to catch weaknesses of the numerical methods based on their non-fulfillm

On dynamic foward rate modeling and principal component analysis

In this paper, we show how to construct dynamic forward rate models in terms of exogenously specified eigenfunctions (or factor loadings). We also show how to link forward rate models with different number of driving Brownian motions to each other in a way consistent with the implied eigenfunctions. Finally, we discuss how to best parameterize the models in the sense of maximizing the number of fr

Tagging fast neutrons from a 252Cf fission-fragment source

Coincidence and time-of-flight measurement techniques are employed to tag fission neutrons emitted from a 252Cf source sealed on one side with a very thin layer of Au. The source is positioned within a gaseous 4He scintillator detector. Together with α particles, both light and heavy fission fragments pass through the thin layer of Au and are detected. The fragments enable the corresponding fissio

A comparison of untagged gamma-ray and tagged-neutron yields from 241AmBe and 238PuBe sources

Untagged gamma-ray and tagged-neutron yields from 241AmBe and 238PuBe mixed-field sources have been measured. Gamma-ray spectroscopy measurements from 1 to 5 MeV were performed in an open environment using a CeBr3 detector and the same experimental conditions for both sources. The shapes of the distributions are very similar and agree well with previous data. Tagged-neutron measurements from 2 to

Correlation of CT-based regional cardiac function (SQUEEZ) with myocardial strain calculated from tagged MRI : an experimental study

The objective of this study was to investigate the correlation between local myocardial function estimates from CT and myocardial strain from tagged MRI in the same heart. Accurate detection of regional myocardial dysfunction can be an important finding in the diagnosis of functionally significant coronary artery disease. Tagged MRI is currently a reference standard for noninvasive regional myocar

Temporal and spatial characteristics of the area at risk investigated using computed tomography and T1-weighted magnetic resonance imaging

AIMS: Cardiovascular magnetic resonance (CMR) imaging can measure the myocardial area at risk (AAR), but the technique has received criticism for inadequate validation. CMR commonly depicts an AAR that is wider than the infarct, which in turn would require a lateral perfusion gradient within the AAR. We investigated the presence of a lateral perfusion gradient within the AAR and validated CMR meas